3-DIMENSIONAL FREE-SURFACE MODELING IN AN UNSTRUCTURED MESH ENVIRONMENT FOR METAL PROCESSING APPLICATIONS

In the casting of metals, tundish flow, welding, converters, and other metal processing applications, the behaviour of the fluid surface is important. In aluminium alloys, for example, oxides formed on the surf ace may be drawn into the body of the melt where they act as faults in the solidified product affecting cast quality. For this reason, accur ate description of wave behaviour, air entrapment, and other effects n eed to be modelled, in the presence of heat transfer and possibly phas e change. The authors have developed a single-phase algorithm for mode lling this problem. The Scalar Equation Algorithm (SEA) (see Refs. [1, 2]), enables the transport of the property discontinuity representing the free surface through a fixed grid. An extension of this method to unstructured mesh codes is presented here, together with validation. T he new method employs a TVD flux limiter in conjunction with a ray-tra cing algorithm, to ensure a sharp bound interface. Applications of the method are in the filling and emptying of mould cavities, with heat t ransfer and phase change. (C) 1998 Elsevier Science Inc. All rights re served.